Spring



March 7, 1939. w E. DILLEHUNT SPRING Filed July 29, 1938 Patented Mar. 7, 1 939 PATENT OFFICE SPRING William E. Dillehunt, Baltimore, Md.

Application July 29, 1938, Serial No. 221,894 I 6 Claims.

The invention relates to a vehicle spring to serve'the purpose of the present standard multiple leaf type now used on practically all wheeled vehicles.

The object of the invention is to form a plurality of spring leaves from a single sheet, the leaves in the finished form being in a single piece.

The improved spring of the invention is made "from a tapered shape or blank of sheet metal which is folded accordion wise with the folds or creases extending transversely to the direction of the taper and'in the direction of the length of the spring and rolled or pressed into the form of the complete vehicle spring.

Whilein the preferred form the entire spring is formed in a single piece, the number of leaves connected in this way is a matter of choice, the number of pieces in a complete spring not being ;strictly limited in broader scope of the invention. 7

Advantages of the invention are that the improved spring is more durable than the present product and on account of the folds it offers resistance in both vertical directions, i. e. up-

wardly and'downwardly so that the necessity for shock absorbers is. largely eliminated and also onaccount of the folds it has increased resistance to side sway and increased dura- ;bility.

Further advantages are the elimination of spring straps orclamps, or the reduction of the number required, and particularly the elimination of spring bolts, and hence of the necessity for punching the spring leaves which punching or boring greatly reduces the strength and durability of the finished product. s

The new spring has the further advantage that it is adapted to quick and cheap production; and it therefore constitutes tionto mass production on a profitable and satisfactory basis of automobiles and other wheeledvehicles.

In accordance with the method of production so far devised, which is not essential to the product, a tapered pattern or blank of sheet metal of the proper thickness is first cut and then plaited or corrugated by passing through a corrugating machine in a direction transverse to the taper, i. e. transverse to the direction in which it is tapered, and in the direction of the length of the completed spring. It is then pressed in the direction of the' taper, and run through rollers to complete the folds and flatten the spring as more fully hereinafter described. The

an important contribudesired curvature or. set may be imparted by a suitable arrangement of the rollers.

.In the accompanying drawing, I have illustrated a spring constructed in accordance with the invention in the preferred form, and also showing a modified form of blank for producing a slightly different form of spring.

In the drawing:

Figure 1 is side elevation of the improved spring assembled for use, or installation in the vehicle.

Figure 2 is a bottom plan view of the same, the long leaf being on top, and the short leaf underneath for the underslung type of vehicle.

Figure 3 is a top plan of spring thus assembled.

Figure 4 is a transverse section on the line 44 in Figure l. I

Figure 5 is a plan of a blank from which the spring may be made, the fold line being indicated in broken lines.

Figure 6 is a plan view of a modified form of blank. 7

Referring tothe drawing by numerals, each of which is used to indicate the same or similar parts in the different figures spring I, as shown,

plurality of the leaves of the present standard 2 leaf type of vehicle spring.

In the form of the invention shown the spring I consists of a main leaf 2 assembly as the top leaf. This is the longleaf which extends from one spring shackle to the other, the top or long leaf 2 being provided at each end with eyes 5 for engagement with the shackle bolt. The spring also comprises oppo sitely to the top leaf 2 a short bottom leaf 3 of minimum length. Between the top leaf 2 and the bottom 3 there are a plurality of leaves 4 which are uniformly varied and increased in length from the short leaf or bottom leaf 3 to the long or top leaf 2. The spaces between the overlapping ends being shown at 6, 1, and 8 in Figure 2 which, as pointed out, is a bottom plan vlew.

Figure 5 illustrates a blank from which a spring may be made in accordance with the invention, the blank being indicated by reference shown in the present I character 9, and being subject to considerable variation within the scope of the invention.

In the form shown, this blank has an elongated straight portion ID shown at the top which has extensions H at the ends beyond the main portion I2 of the blank for forming the eyes 5. Immediately below this extended portion 10, the main portion of the blank at I2 is of reduced dimensions at I4, providing for the shorter leaves. From this point down the width of the blank which corresponds to the length of the spring is of uniformly reducing taper to the narrowest or shortest portion IE3 at the-bottom which corresponds to the short leaf 3 in Figures 1 and 2.

The broken line I6 which extends transversely To produce these folds which may be described as accordion folds, the blank may be passed in the direction of the line l6 through the corrugating machine, preferably one which produces corrugations which have sharp edged peaks, and valleys of V cross-section.

When the blank has been corrugated or creased, pressure is applied in the direction of the taper, that is at iii and I5, the top Ill and the bottom l5 being pressed together to close the folds or corrugations. The eyes 5 are then formed and the springmay be treated as complete and ready for installation, being suitably clamped to the axle, and being engaged in accordance with the established practice with the spring shackles by the way of the eyes 5 provided for this purpose.

In accordance with the preferred practice, the spring may to advantage be passed before the eyes 5 are formed, through pressing rollers being normally passed through the rollers, in the direction of its length to complete the closure of the folds. The desired set may be imparted by suitable arrangement of rollers as understood in the spring art.

Figure 4 which is a cross section on the line 4-4 in Figure 1, shows the top leaf 2 formed by folding the upper section it! above the first crease or fold line It in such a way that the upper section i6 already identified, forms What may be termed the bottom of the top leaf 2 eliminating what would otherwise be a sharp edge corresponding to the short sharp edge l3 at the bottom in Figure 4 which is the edge of the short bottom leaf 3. This requires an initial folding under of the top section H) which must he performed separately, and cannot conveniently be formed by pressing in the direction lfii5 as already described, and it may not be considered essential to the production of a satisfactory spring.

The curved edges or creases ll of the folds in the finished spring as shown in Figure 6, corresponding to the broken line E5 on which the blank is folded, together form the side surfaces of the spring, and these folds are of importance in that folded edges indicated at I! in Figure 6 is for any reason considered undesirable, the edges of the leaves may be separated by forming the blank in the initial process of cutting it from the sheet metal with slots 18 preferably extending inwardly from the outer inclined edges of the blank, and inwardly from the outer ends of the areas corresponding to the respective leaves.

The center zone 2|, or any suitable zone indicated by reference character 2|, or any preferred area, may be left uncut, whereby the spring leaves are connected to form an assembly of a plurality of leaves, or preferably, of all the leaves of a single spring in one piece. This blank would be assembled as previously described, 1. e. plaited or corrugated, and pressed, and the area or areas 2! may be chosen as desired to connect the leaves in a single case leaving the ends or any preferred portions of the leaves free to slide relatively to each other substantially as in the present type-of leaf spring, but this type still has the advantage of being formed with a plurality of leaves in a singlepiece, and it has the advantage of q ick and easy construction, and also the advantage that no pins are required to connect the leaves to hold them in assembled relation, and the leaves are therefore unperforated, and of the full strength of the combined sheet metal.

The spring as described may be made of any preferred variety of metal, being preferably of a steel which can be given the desired temper after the spring is completed, or itmay, under suitable circumstances, be made of a metal that does not require subsequent tempering or it may be tempered after assembling in the form shown.

The spring made of the preferred form of blank, Figure 5, and to possibly a less degree the spring made of the blank, Figure 6, has the advantage of greater strength from a thinner grade of metal than that used for the corresponding leaf springs of the present type, and the further advantages as pointed out in the preamble that it can be quickly and cheaply produced, that it requires no center pin, and is, therefore, stronger and more durable, and that it resists both the upward and downward tendency of the body to a similar degree, reducing the necessity for shock absorbers, that it reduces side sway to a greater extent than the present type of leaf spring, and is more durable than the present product, and particularly adapted to mass production of the standard springs for vehicles.

I have thus described a spring and a methodof making the same, embodying the features of my invention in a preferred and in a modified form, the description being specific and in detail inorder that the manner of constructing, applying, operating, and using the invention, may be fully understood. However, the specific terms herein are used descriptively rather than in a limiting sense, the scope of the invention being defined in the claims. I

What I claim as new, and desire to secure by Letters Patent is:

1. A spring having substantially the shape and function of an assembled leaf spring for wheeled vehicles consisting of a main leaf of the full length spring, and successively shorter leaves, a plurality of said leaves consisting of a single piece of. folded sheet metal, the adjacent longitudinal edges only of the leaves, comprising creases connecting the edges of successive adjacent leaves.

2. A leaf spring consisting of a single sheet of metal, of tapered form in successively overlying,

fiat folds of varying lengths, the folds comprising the short leaf at one side of the spring, and a main long leaf at the other side of the spring, and leaves of intermediate lengths between the short and long leaf, all being of a single piece of sheet metal, the folds being connected by creases extending along the longitudinal edges only of the leaves.

3. A leaf spring having a plurality of leaves consisting of a single piece of sheet metal, successive leaves being connected by a folded portion of the metal at the edge of the leaves, the metal being slotted along the line of said folded portions for part of the length of the leaves.

4. A leaf spring having a plurality of leaves consisting of a single piece of sheet metal, successive leaves being connected by a folded portion of the metal at the edge of the leaves, the metal being slotted along the line of said folded portions for part of the length of the leaves, and

being continuous near the centers of the lengths of the leaves.

5. A leaf spring having leaves of varying lengths, the spring consisting of a single piece of sheet metal which in flattened condition is of tapered outline, the sheet metal being creased transversely to the direction of taper, the creases being spaced in accordance with the width of the leaves and the sheet metal being folded in multiple thickness on said creases, the portions between the creases comprising the leaves being closely related in substantial registration.

6. A leaf spring consisting of a single piece of sheet metal comprising leaves of varying lengths, the sheet metal being of tapered outline when flattened and being creased transversely to the direction of taper and folded in multiple thickness at said creases, the portions between the creases being the leaves.

WILLIAM E. DILLEHUNTL 

